Real numbers between and , inclusive, are chosen in the following manner. A biased coin is flipped such that the probability of landing heads is . If it lands heads, then it is flipped again (fair coin) and the chosen number is if the second flip is heads and if the second flip is tails. On the other hand, if the first coin flip is tails, then the number is chosen uniformly at random from the closed interval . Two random numbers and are chosen independently in this manner. What is the probability that ?
5/18
1/3
7/18
4/9
1/2